Real-time modelling and forecasting
How can we better prepare
for the next pandemic?
Sebastian Funk (@sbfnk)
https://epiforecasts.io
14 June, 2022
BIRS-UBCO Workshop on "Preparing for the next pandemic"
Banff International Research Station
Mechanistic models support causal understanding, but predictions can have value in their own right
Desai et al., Health Secur, 2019
Keeling et al., Stat Meth Med Res, 2021
Cramer et al., medRxiv, 2021
Real-time forecasts can inform decision making
Anticipate healthcare demand
Real-time forecasts can inform decision making
Inform interventions
Real-time forecasts can inform decision making
Support clinical trials
Global COVID case forecasts via the renewal equation
\[I(t) = R_t \sum_{\tau} g_{\tau} I_{t-\tau}\]
Abbott et al., Wellcome Open Res, 2020
Gostic et al., PLoS Comp Biol, 2021
Forecasting to inform policy in the UK
Funk et al., medRxiv, 2021
COVID forecast hubs
Reich et al., Am J Public Health, 2022
- How good were COVID forecasts?
- How could COVID forecasts be improved?
- What can we conclude for the next pandemic?
How good were COVID forecasts?
We can compare forecasts using
proper scoring rules, e.g.
\[\mathrm{CRPS}(F, x) = \mathbb{E}|X-x| - \frac{1}{2}\mathbb{E}|X-X'|\]
Forecast hubs:
median ensemble outperforms individual models
Sherratt et al., in prep
We can compare forecasts using proper scoring rules, e.g. \[\mathrm{CRPS}(F, x) = \mathbb{E}|X-x| - \frac{1}{2}\mathbb{E}|X-X'|\] but these only tell us about relative quality of forecasts
Absolute quality of forecasts #1: baseline models
Absolute quality of forecasts #2: human vs. machine
Bosse et al., medRxiv, 2022
Absolute quality of forecasts #3: calibration
Sherratt et al., in prep
How could COVID forecasts be improved?
Including possible predictors #1: cases
Meakin et al., BMC Medicine, 2021
Including possible predictors #2: contacts
Munday et al., in prep
Including possible predictors #3: variants
Abbott et al., medRxiv, 2021
What can we conclude for the next pandemic?
Summary
- Outbreak forecasting is difficult
- Ensembles perform best, but can be difficult to interpret
Forecasting and nowcasting will remain relevant
UKHSA, 2022
Nowcasting of delayed reports
https://covid19nowcasthub.de
https://epiforecasts.io/epinowcast/
New initiatives
We need collaborative efforts, using standardised datasets to compare methods and generating sustainable tools
Acknowledgements
EpiForecasts group (https://epiforecasts.io)
Akira Endo, Hannah Choi, Hugo Gruson, James Munday, Kath Sherratt, Nikos Bosse, Sam Abbott, Sophie Meakin
Johannes Bracher, Nick Reich and other collaborators
